Permanent Steam Blowing design - Supercritical Coal fired boiler

[Roger00]

Hi,

if one company decides to install permanent steam blowing line (blowoff line) to the atmosphere for Supercritical coal fired boiler. The installation is done by modifying the superheater header at each side. what are the related clauses for this steam blow line in asme section 1.

thanks.

 

[Duwe6]

Look at the "continuous blowdown" portion of the boiler boundary sketch in B31.1 Figure 100.1.2

 

[Roger00]

thanks Duwe, but i dont think so because it is blowdown/blowoff, what i am looking is the steam blowing. Shall i considered as steam piping (Boiler external piping, b31.1) since it is connected to the SH oulet header and the piping will have 2 block valves with piping and the block valves have min. P and T to MAWP. any opinion?

For "blowoff" in section 1, PG.59.3 and B31.1. 122.1.4. is this considered as steam blow piping that has diameter over 4", in PG59.32. and 59.3.5 the blowoff is restricted to max. 2.5". I am thinking that this is the blowoff is for water just like water blowdown.

thanks